forked from illumos/gcc
/
explow.c
1921 lines (1588 loc) · 55.4 KB
/
explow.c
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/* Subroutines for manipulating rtx's in semantically interesting ways.
Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "diagnostic-core.h"
#include "rtl.h"
#include "tree.h"
#include "tm_p.h"
#include "flags.h"
#include "except.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
#include "libfuncs.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "ggc.h"
#include "recog.h"
#include "langhooks.h"
#include "target.h"
#include "common/common-target.h"
#include "output.h"
static rtx break_out_memory_refs (rtx);
/* Truncate and perhaps sign-extend C as appropriate for MODE. */
HOST_WIDE_INT
trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
{
int width = GET_MODE_PRECISION (mode);
/* You want to truncate to a _what_? */
gcc_assert (SCALAR_INT_MODE_P (mode));
/* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
if (mode == BImode)
return c & 1 ? STORE_FLAG_VALUE : 0;
/* Sign-extend for the requested mode. */
if (width < HOST_BITS_PER_WIDE_INT)
{
HOST_WIDE_INT sign = 1;
sign <<= width - 1;
c &= (sign << 1) - 1;
c ^= sign;
c -= sign;
}
return c;
}
/* Return an rtx for the sum of X and the integer C. */
rtx
plus_constant (rtx x, HOST_WIDE_INT c)
{
RTX_CODE code;
rtx y;
enum machine_mode mode;
rtx tem;
int all_constant = 0;
if (c == 0)
return x;
restart:
code = GET_CODE (x);
mode = GET_MODE (x);
y = x;
switch (code)
{
case CONST_INT:
return GEN_INT (INTVAL (x) + c);
case CONST_DOUBLE:
{
unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
unsigned HOST_WIDE_INT l2 = c;
HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
unsigned HOST_WIDE_INT lv;
HOST_WIDE_INT hv;
add_double (l1, h1, l2, h2, &lv, &hv);
return immed_double_const (lv, hv, VOIDmode);
}
case MEM:
/* If this is a reference to the constant pool, try replacing it with
a reference to a new constant. If the resulting address isn't
valid, don't return it because we have no way to validize it. */
if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
{
tem
= force_const_mem (GET_MODE (x),
plus_constant (get_pool_constant (XEXP (x, 0)),
c));
if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
return tem;
}
break;
case CONST:
/* If adding to something entirely constant, set a flag
so that we can add a CONST around the result. */
x = XEXP (x, 0);
all_constant = 1;
goto restart;
case SYMBOL_REF:
case LABEL_REF:
all_constant = 1;
break;
case PLUS:
/* The interesting case is adding the integer to a sum.
Look for constant term in the sum and combine
with C. For an integer constant term, we make a combined
integer. For a constant term that is not an explicit integer,
we cannot really combine, but group them together anyway.
Restart or use a recursive call in case the remaining operand is
something that we handle specially, such as a SYMBOL_REF.
We may not immediately return from the recursive call here, lest
all_constant gets lost. */
if (CONST_INT_P (XEXP (x, 1)))
{
c += INTVAL (XEXP (x, 1));
if (GET_MODE (x) != VOIDmode)
c = trunc_int_for_mode (c, GET_MODE (x));
x = XEXP (x, 0);
goto restart;
}
else if (CONSTANT_P (XEXP (x, 1)))
{
x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c));
c = 0;
}
else if (find_constant_term_loc (&y))
{
/* We need to be careful since X may be shared and we can't
modify it in place. */
rtx copy = copy_rtx (x);
rtx *const_loc = find_constant_term_loc (©);
*const_loc = plus_constant (*const_loc, c);
x = copy;
c = 0;
}
break;
default:
break;
}
if (c != 0)
x = gen_rtx_PLUS (mode, x, GEN_INT (c));
if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
return x;
else if (all_constant)
return gen_rtx_CONST (mode, x);
else
return x;
}
/* If X is a sum, return a new sum like X but lacking any constant terms.
Add all the removed constant terms into *CONSTPTR.
X itself is not altered. The result != X if and only if
it is not isomorphic to X. */
rtx
eliminate_constant_term (rtx x, rtx *constptr)
{
rtx x0, x1;
rtx tem;
if (GET_CODE (x) != PLUS)
return x;
/* First handle constants appearing at this level explicitly. */
if (CONST_INT_P (XEXP (x, 1))
&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
XEXP (x, 1)))
&& CONST_INT_P (tem))
{
*constptr = tem;
return eliminate_constant_term (XEXP (x, 0), constptr);
}
tem = const0_rtx;
x0 = eliminate_constant_term (XEXP (x, 0), &tem);
x1 = eliminate_constant_term (XEXP (x, 1), &tem);
if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
*constptr, tem))
&& CONST_INT_P (tem))
{
*constptr = tem;
return gen_rtx_PLUS (GET_MODE (x), x0, x1);
}
return x;
}
/* Return an rtx for the size in bytes of the value of EXP. */
rtx
expr_size (tree exp)
{
tree size;
if (TREE_CODE (exp) == WITH_SIZE_EXPR)
size = TREE_OPERAND (exp, 1);
else
{
size = tree_expr_size (exp);
gcc_assert (size);
gcc_assert (size == SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, exp));
}
return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), EXPAND_NORMAL);
}
/* Return a wide integer for the size in bytes of the value of EXP, or -1
if the size can vary or is larger than an integer. */
HOST_WIDE_INT
int_expr_size (tree exp)
{
tree size;
if (TREE_CODE (exp) == WITH_SIZE_EXPR)
size = TREE_OPERAND (exp, 1);
else
{
size = tree_expr_size (exp);
gcc_assert (size);
}
if (size == 0 || !host_integerp (size, 0))
return -1;
return tree_low_cst (size, 0);
}
/* Return a copy of X in which all memory references
and all constants that involve symbol refs
have been replaced with new temporary registers.
Also emit code to load the memory locations and constants
into those registers.
If X contains no such constants or memory references,
X itself (not a copy) is returned.
If a constant is found in the address that is not a legitimate constant
in an insn, it is left alone in the hope that it might be valid in the
address.
X may contain no arithmetic except addition, subtraction and multiplication.
Values returned by expand_expr with 1 for sum_ok fit this constraint. */
static rtx
break_out_memory_refs (rtx x)
{
if (MEM_P (x)
|| (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
&& GET_MODE (x) != VOIDmode))
x = force_reg (GET_MODE (x), x);
else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
|| GET_CODE (x) == MULT)
{
rtx op0 = break_out_memory_refs (XEXP (x, 0));
rtx op1 = break_out_memory_refs (XEXP (x, 1));
if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
x = simplify_gen_binary (GET_CODE (x), GET_MODE (x), op0, op1);
}
return x;
}
/* Given X, a memory address in address space AS' pointer mode, convert it to
an address in the address space's address mode, or vice versa (TO_MODE says
which way). We take advantage of the fact that pointers are not allowed to
overflow by commuting arithmetic operations over conversions so that address
arithmetic insns can be used. */
rtx
convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
rtx x, addr_space_t as ATTRIBUTE_UNUSED)
{
#ifndef POINTERS_EXTEND_UNSIGNED
gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
return x;
#else /* defined(POINTERS_EXTEND_UNSIGNED) */
enum machine_mode pointer_mode, address_mode, from_mode;
rtx temp;
enum rtx_code code;
/* If X already has the right mode, just return it. */
if (GET_MODE (x) == to_mode)
return x;
pointer_mode = targetm.addr_space.pointer_mode (as);
address_mode = targetm.addr_space.address_mode (as);
from_mode = to_mode == pointer_mode ? address_mode : pointer_mode;
/* Here we handle some special cases. If none of them apply, fall through
to the default case. */
switch (GET_CODE (x))
{
case CONST_INT:
case CONST_DOUBLE:
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode))
code = TRUNCATE;
else if (POINTERS_EXTEND_UNSIGNED < 0)
break;
else if (POINTERS_EXTEND_UNSIGNED > 0)
code = ZERO_EXTEND;
else
code = SIGN_EXTEND;
temp = simplify_unary_operation (code, to_mode, x, from_mode);
if (temp)
return temp;
break;
case SUBREG:
if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x)))
&& GET_MODE (SUBREG_REG (x)) == to_mode)
return SUBREG_REG (x);
break;
case LABEL_REF:
temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
return temp;
break;
case SYMBOL_REF:
temp = shallow_copy_rtx (x);
PUT_MODE (temp, to_mode);
return temp;
break;
case CONST:
return gen_rtx_CONST (to_mode,
convert_memory_address_addr_space
(to_mode, XEXP (x, 0), as));
break;
case PLUS:
case MULT:
/* FIXME: For addition, we used to permute the conversion and
addition operation only if one operand is a constant and
converting the constant does not change it or if one operand
is a constant and we are using a ptr_extend instruction
(POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
may overflow/underflow. We relax the condition to include
zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
parts of the compiler depend on it. See PR 49721.
We can always safely permute them if we are making the address
narrower. */
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
|| (GET_CODE (x) == PLUS
&& CONST_INT_P (XEXP (x, 1))
&& (POINTERS_EXTEND_UNSIGNED != 0
|| XEXP (x, 1) == convert_memory_address_addr_space
(to_mode, XEXP (x, 1), as))))
return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
convert_memory_address_addr_space
(to_mode, XEXP (x, 0), as),
XEXP (x, 1));
break;
default:
break;
}
return convert_modes (to_mode, from_mode,
x, POINTERS_EXTEND_UNSIGNED);
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
}
/* Return something equivalent to X but valid as a memory address for something
of mode MODE in the named address space AS. When X is not itself valid,
this works by copying X or subexpressions of it into registers. */
rtx
memory_address_addr_space (enum machine_mode mode, rtx x, addr_space_t as)
{
rtx oldx = x;
enum machine_mode address_mode = targetm.addr_space.address_mode (as);
x = convert_memory_address_addr_space (address_mode, x, as);
/* By passing constant addresses through registers
we get a chance to cse them. */
if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
x = force_reg (address_mode, x);
/* We get better cse by rejecting indirect addressing at this stage.
Let the combiner create indirect addresses where appropriate.
For now, generate the code so that the subexpressions useful to share
are visible. But not if cse won't be done! */
else
{
if (! cse_not_expected && !REG_P (x))
x = break_out_memory_refs (x);
/* At this point, any valid address is accepted. */
if (memory_address_addr_space_p (mode, x, as))
goto done;
/* If it was valid before but breaking out memory refs invalidated it,
use it the old way. */
if (memory_address_addr_space_p (mode, oldx, as))
{
x = oldx;
goto done;
}
/* Perform machine-dependent transformations on X
in certain cases. This is not necessary since the code
below can handle all possible cases, but machine-dependent
transformations can make better code. */
{
rtx orig_x = x;
x = targetm.addr_space.legitimize_address (x, oldx, mode, as);
if (orig_x != x && memory_address_addr_space_p (mode, x, as))
goto done;
}
/* PLUS and MULT can appear in special ways
as the result of attempts to make an address usable for indexing.
Usually they are dealt with by calling force_operand, below.
But a sum containing constant terms is special
if removing them makes the sum a valid address:
then we generate that address in a register
and index off of it. We do this because it often makes
shorter code, and because the addresses thus generated
in registers often become common subexpressions. */
if (GET_CODE (x) == PLUS)
{
rtx constant_term = const0_rtx;
rtx y = eliminate_constant_term (x, &constant_term);
if (constant_term == const0_rtx
|| ! memory_address_addr_space_p (mode, y, as))
x = force_operand (x, NULL_RTX);
else
{
y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
if (! memory_address_addr_space_p (mode, y, as))
x = force_operand (x, NULL_RTX);
else
x = y;
}
}
else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
x = force_operand (x, NULL_RTX);
/* If we have a register that's an invalid address,
it must be a hard reg of the wrong class. Copy it to a pseudo. */
else if (REG_P (x))
x = copy_to_reg (x);
/* Last resort: copy the value to a register, since
the register is a valid address. */
else
x = force_reg (address_mode, x);
}
done:
gcc_assert (memory_address_addr_space_p (mode, x, as));
/* If we didn't change the address, we are done. Otherwise, mark
a reg as a pointer if we have REG or REG + CONST_INT. */
if (oldx == x)
return x;
else if (REG_P (x))
mark_reg_pointer (x, BITS_PER_UNIT);
else if (GET_CODE (x) == PLUS
&& REG_P (XEXP (x, 0))
&& CONST_INT_P (XEXP (x, 1)))
mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
/* OLDX may have been the address on a temporary. Update the address
to indicate that X is now used. */
update_temp_slot_address (oldx, x);
return x;
}
/* Convert a mem ref into one with a valid memory address.
Pass through anything else unchanged. */
rtx
validize_mem (rtx ref)
{
if (!MEM_P (ref))
return ref;
ref = use_anchored_address (ref);
if (memory_address_addr_space_p (GET_MODE (ref), XEXP (ref, 0),
MEM_ADDR_SPACE (ref)))
return ref;
/* Don't alter REF itself, since that is probably a stack slot. */
return replace_equiv_address (ref, XEXP (ref, 0));
}
/* If X is a memory reference to a member of an object block, try rewriting
it to use an anchor instead. Return the new memory reference on success
and the old one on failure. */
rtx
use_anchored_address (rtx x)
{
rtx base;
HOST_WIDE_INT offset;
if (!flag_section_anchors)
return x;
if (!MEM_P (x))
return x;
/* Split the address into a base and offset. */
base = XEXP (x, 0);
offset = 0;
if (GET_CODE (base) == CONST
&& GET_CODE (XEXP (base, 0)) == PLUS
&& CONST_INT_P (XEXP (XEXP (base, 0), 1)))
{
offset += INTVAL (XEXP (XEXP (base, 0), 1));
base = XEXP (XEXP (base, 0), 0);
}
/* Check whether BASE is suitable for anchors. */
if (GET_CODE (base) != SYMBOL_REF
|| !SYMBOL_REF_HAS_BLOCK_INFO_P (base)
|| SYMBOL_REF_ANCHOR_P (base)
|| SYMBOL_REF_BLOCK (base) == NULL
|| !targetm.use_anchors_for_symbol_p (base))
return x;
/* Decide where BASE is going to be. */
place_block_symbol (base);
/* Get the anchor we need to use. */
offset += SYMBOL_REF_BLOCK_OFFSET (base);
base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset,
SYMBOL_REF_TLS_MODEL (base));
/* Work out the offset from the anchor. */
offset -= SYMBOL_REF_BLOCK_OFFSET (base);
/* If we're going to run a CSE pass, force the anchor into a register.
We will then be able to reuse registers for several accesses, if the
target costs say that that's worthwhile. */
if (!cse_not_expected)
base = force_reg (GET_MODE (base), base);
return replace_equiv_address (x, plus_constant (base, offset));
}
/* Copy the value or contents of X to a new temp reg and return that reg. */
rtx
copy_to_reg (rtx x)
{
rtx temp = gen_reg_rtx (GET_MODE (x));
/* If not an operand, must be an address with PLUS and MULT so
do the computation. */
if (! general_operand (x, VOIDmode))
x = force_operand (x, temp);
if (x != temp)
emit_move_insn (temp, x);
return temp;
}
/* Like copy_to_reg but always give the new register mode Pmode
in case X is a constant. */
rtx
copy_addr_to_reg (rtx x)
{
return copy_to_mode_reg (Pmode, x);
}
/* Like copy_to_reg but always give the new register mode MODE
in case X is a constant. */
rtx
copy_to_mode_reg (enum machine_mode mode, rtx x)
{
rtx temp = gen_reg_rtx (mode);
/* If not an operand, must be an address with PLUS and MULT so
do the computation. */
if (! general_operand (x, VOIDmode))
x = force_operand (x, temp);
gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
if (x != temp)
emit_move_insn (temp, x);
return temp;
}
/* Load X into a register if it is not already one.
Use mode MODE for the register.
X should be valid for mode MODE, but it may be a constant which
is valid for all integer modes; that's why caller must specify MODE.
The caller must not alter the value in the register we return,
since we mark it as a "constant" register. */
rtx
force_reg (enum machine_mode mode, rtx x)
{
rtx temp, insn, set;
if (REG_P (x))
return x;
if (general_operand (x, mode))
{
temp = gen_reg_rtx (mode);
insn = emit_move_insn (temp, x);
}
else
{
temp = force_operand (x, NULL_RTX);
if (REG_P (temp))
insn = get_last_insn ();
else
{
rtx temp2 = gen_reg_rtx (mode);
insn = emit_move_insn (temp2, temp);
temp = temp2;
}
}
/* Let optimizers know that TEMP's value never changes
and that X can be substituted for it. Don't get confused
if INSN set something else (such as a SUBREG of TEMP). */
if (CONSTANT_P (x)
&& (set = single_set (insn)) != 0
&& SET_DEST (set) == temp
&& ! rtx_equal_p (x, SET_SRC (set)))
set_unique_reg_note (insn, REG_EQUAL, x);
/* Let optimizers know that TEMP is a pointer, and if so, the
known alignment of that pointer. */
{
unsigned align = 0;
if (GET_CODE (x) == SYMBOL_REF)
{
align = BITS_PER_UNIT;
if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x)))
align = DECL_ALIGN (SYMBOL_REF_DECL (x));
}
else if (GET_CODE (x) == LABEL_REF)
align = BITS_PER_UNIT;
else if (GET_CODE (x) == CONST
&& GET_CODE (XEXP (x, 0)) == PLUS
&& GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
&& CONST_INT_P (XEXP (XEXP (x, 0), 1)))
{
rtx s = XEXP (XEXP (x, 0), 0);
rtx c = XEXP (XEXP (x, 0), 1);
unsigned sa, ca;
sa = BITS_PER_UNIT;
if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
if (INTVAL (c) == 0)
align = sa;
else
{
ca = ctz_hwi (INTVAL (c)) * BITS_PER_UNIT;
align = MIN (sa, ca);
}
}
if (align || (MEM_P (x) && MEM_POINTER (x)))
mark_reg_pointer (temp, align);
}
return temp;
}
/* If X is a memory ref, copy its contents to a new temp reg and return
that reg. Otherwise, return X. */
rtx
force_not_mem (rtx x)
{
rtx temp;
if (!MEM_P (x) || GET_MODE (x) == BLKmode)
return x;
temp = gen_reg_rtx (GET_MODE (x));
if (MEM_POINTER (x))
REG_POINTER (temp) = 1;
emit_move_insn (temp, x);
return temp;
}
/* Copy X to TARGET (if it's nonzero and a reg)
or to a new temp reg and return that reg.
MODE is the mode to use for X in case it is a constant. */
rtx
copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
{
rtx temp;
if (target && REG_P (target))
temp = target;
else
temp = gen_reg_rtx (mode);
emit_move_insn (temp, x);
return temp;
}
/* Return the mode to use to pass or return a scalar of TYPE and MODE.
PUNSIGNEDP points to the signedness of the type and may be adjusted
to show what signedness to use on extension operations.
FOR_RETURN is nonzero if the caller is promoting the return value
of FNDECL, else it is for promoting args. */
enum machine_mode
promote_function_mode (const_tree type, enum machine_mode mode, int *punsignedp,
const_tree funtype, int for_return)
{
/* Called without a type node for a libcall. */
if (type == NULL_TREE)
{
if (INTEGRAL_MODE_P (mode))
return targetm.calls.promote_function_mode (NULL_TREE, mode,
punsignedp, funtype,
for_return);
else
return mode;
}
switch (TREE_CODE (type))
{
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
case POINTER_TYPE: case REFERENCE_TYPE:
return targetm.calls.promote_function_mode (type, mode, punsignedp, funtype,
for_return);
default:
return mode;
}
}
/* Return the mode to use to store a scalar of TYPE and MODE.
PUNSIGNEDP points to the signedness of the type and may be adjusted
to show what signedness to use on extension operations. */
enum machine_mode
promote_mode (const_tree type ATTRIBUTE_UNUSED, enum machine_mode mode,
int *punsignedp ATTRIBUTE_UNUSED)
{
#ifdef PROMOTE_MODE
enum tree_code code;
int unsignedp;
#endif
/* For libcalls this is invoked without TYPE from the backends
TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
case. */
if (type == NULL_TREE)
return mode;
/* FIXME: this is the same logic that was there until GCC 4.4, but we
probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
is not defined. The affected targets are M32C, S390, SPARC. */
#ifdef PROMOTE_MODE
code = TREE_CODE (type);
unsignedp = *punsignedp;
switch (code)
{
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
PROMOTE_MODE (mode, unsignedp, type);
*punsignedp = unsignedp;
return mode;
break;
#ifdef POINTERS_EXTEND_UNSIGNED
case REFERENCE_TYPE:
case POINTER_TYPE:
*punsignedp = POINTERS_EXTEND_UNSIGNED;
return targetm.addr_space.address_mode
(TYPE_ADDR_SPACE (TREE_TYPE (type)));
break;
#endif
default:
return mode;
}
#else
return mode;
#endif
}
/* Use one of promote_mode or promote_function_mode to find the promoted
mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
of DECL after promotion. */
enum machine_mode
promote_decl_mode (const_tree decl, int *punsignedp)
{
tree type = TREE_TYPE (decl);
int unsignedp = TYPE_UNSIGNED (type);
enum machine_mode mode = DECL_MODE (decl);
enum machine_mode pmode;
if (TREE_CODE (decl) == RESULT_DECL
|| TREE_CODE (decl) == PARM_DECL)
pmode = promote_function_mode (type, mode, &unsignedp,
TREE_TYPE (current_function_decl), 2);
else
pmode = promote_mode (type, mode, &unsignedp);
if (punsignedp)
*punsignedp = unsignedp;
return pmode;
}
/* Controls the behaviour of {anti_,}adjust_stack. */
static bool suppress_reg_args_size;
/* A helper for adjust_stack and anti_adjust_stack. */
static void
adjust_stack_1 (rtx adjust, bool anti_p)
{
rtx temp, insn;
#ifndef STACK_GROWS_DOWNWARD
/* Hereafter anti_p means subtract_p. */
anti_p = !anti_p;
#endif
temp = expand_binop (Pmode,
anti_p ? sub_optab : add_optab,
stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
OPTAB_LIB_WIDEN);
if (temp != stack_pointer_rtx)
insn = emit_move_insn (stack_pointer_rtx, temp);
else
{
insn = get_last_insn ();
temp = single_set (insn);
gcc_assert (temp != NULL && SET_DEST (temp) == stack_pointer_rtx);
}
if (!suppress_reg_args_size)
add_reg_note (insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
}
/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
This pops when ADJUST is positive. ADJUST need not be constant. */
void
adjust_stack (rtx adjust)
{
if (adjust == const0_rtx)
return;
/* We expect all variable sized adjustments to be multiple of
PREFERRED_STACK_BOUNDARY. */
if (CONST_INT_P (adjust))
stack_pointer_delta -= INTVAL (adjust);
adjust_stack_1 (adjust, false);
}
/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
This pushes when ADJUST is positive. ADJUST need not be constant. */
void
anti_adjust_stack (rtx adjust)
{
if (adjust == const0_rtx)
return;
/* We expect all variable sized adjustments to be multiple of
PREFERRED_STACK_BOUNDARY. */
if (CONST_INT_P (adjust))
stack_pointer_delta += INTVAL (adjust);
adjust_stack_1 (adjust, true);
}
/* Round the size of a block to be pushed up to the boundary required
by this machine. SIZE is the desired size, which need not be constant. */
static rtx
round_push (rtx size)
{
rtx align_rtx, alignm1_rtx;
if (!SUPPORTS_STACK_ALIGNMENT
|| crtl->preferred_stack_boundary == MAX_SUPPORTED_STACK_ALIGNMENT)
{
int align = crtl->preferred_stack_boundary / BITS_PER_UNIT;
if (align == 1)
return size;
if (CONST_INT_P (size))
{
HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align;
if (INTVAL (size) != new_size)
size = GEN_INT (new_size);
return size;
}
align_rtx = GEN_INT (align);
alignm1_rtx = GEN_INT (align - 1);
}
else
{
/* If crtl->preferred_stack_boundary might still grow, use
virtual_preferred_stack_boundary_rtx instead. This will be
substituted by the right value in vregs pass and optimized
during combine. */
align_rtx = virtual_preferred_stack_boundary_rtx;
alignm1_rtx = force_operand (plus_constant (align_rtx, -1), NULL_RTX);
}
/* CEIL_DIV_EXPR needs to worry about the addition overflowing,
but we know it can't. So add ourselves and then do
TRUNC_DIV_EXPR. */
size = expand_binop (Pmode, add_optab, size, alignm1_rtx,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, align_rtx,
NULL_RTX, 1);
size = expand_mult (Pmode, size, align_rtx, NULL_RTX, 1);
return size;
}
/* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
to a previously-created save area. If no save area has been allocated,
this function will allocate one. If a save area is specified, it